Ryan Gosling and Eva Mendes may be one of Hollywood’s hottest couples, but that doesn’t mean they want to live their life in the spotlight.

With a second baby on the way, the notoriously private pair are making sure Esmeralda, 19 months, has all the time – and space – she needs to grow up. The couple are determined to keep their personal lives shielded from the public.

“They may be very private, but they still have a fun life,” a source tells PEOPLE. “They just go out of their way to make sure Esmeralda gets to grow up as normal as possible. Whenever Eva and Ryan are together, they look very happy.”

While Gosling, 35, and Mendes, 42, spend most of their time at home, when it comes to their daughter, they go all out.

For Halloween, both Gosling and Mendes dressed up in costume to evade paparazzi and give Esmerelda a fun night trick-or-treating with friends.

“Eva and Esmeralda wore matching skeleton costumes with face paint. Ryan was unrecognizable with a Grim Reaper mask. Esmeralda looked adorable,” says the source. “She seemed a bit overwhelmed by the whole event and Eva carried her around. Both Ryan and Eva made sure she had a fun Halloween.”

“They were the cutest family,” adds the source.

Like with her first child, Mendes managed to keep her pregnancy under wraps for several months, “[She] just hasn’t ever wanted anyone beyond her close friends and family knowing more than they had to,” an insider previously told PEOPLE.

But the parents are thrilled to add to their growing family. A source previously told PEOPLE that Gosling is “madly in love” with Esmeralda, and Mendes loves life as a mom.